During a pump capacity test, if the net pressure is correct but the nozzle flow (gpm) is too high, what adjustment should be made?

• A. A Discharge gate must be opened further
• B. B Discharge gate must be closed further
• C. C Throttle setting must be increased
• D. D Other discharge is opened to reduce flow

Answer: (B)

When you’re performing a pump capacity test, you want the nozzle pressure and the nozzle flow to meet the target values. If the net pressure is already right but the nozzle flow (gpm) is too high, the adjustment you make is to reduce the discharge flow without changing the pressure balance. Closing the discharge gate further achieves this: it increases the hydraulic resistance and lowers the amount of water flowing to the nozzle, bringing the GPM down to the desired level. Opening the gate or adding another discharge would raise flow, and altering the throttle could disrupt the already correct pressure.